Flying target for trap shooting

ABSTRACT

A flying target or clay pigeon molded from a frangible pitch and clay mixture having an internal surface with sharp interior angles of substantially 125* and 140* formed by intersecting conical surfaces. The 125* angle is located inwardly of the rim, and 140* angle is located beneath the dome. Between the two angles, there is an inwardly protuberant surface portion which provides a thickened wall section for the step to improve trapping strength. The sharp interior angles represent lines of potential fracture which extend circumferentially. A neck portion separates the rim from the step.

Q United States Patent 1 3,572,714

[72] Inventor Erwin M. Lau 3,169,767 2/1965 Bingham 273/105.4Dolton,lll. 3,207,516 9/1965 Kaluzng et a1. 273/1054 g 31%? 1968 PrimaryExaminer-Anton O. Oechsle t d M 1971 Assistant Examiner-Marvin Siskind E4 252 23 hfoducts Co Attorney-label, Baker, York, Jones and DithmarChicago, Ill.

[54.] FLYING TARGET FORTRAPSHOOTING ABSTRAC'l': A flying target or claypigeon molded from a frangible pitch and clay mixture having an internalsurface 11 Claims, 4 Drawlng Figs.

with sharp interior angles of substantially 125 and 140 [52] U-S.C|.273/3054 fo d b intersecting conical surfaces, The 125 angle is 1 lift.(1 F4 .1 located inwardly of the rim, and 140 angle is located beneathField of Search the dome. Between the two angles, there is an inwardlyprotu- 273/1054 berant surface portion which provides a thickened wallsection for the step to improve trapping strength. The sharp in- [56]References cued terior angles represent lines of potential fracturewhich extend UNITED STATES PATENTS circumferentially. A neck portionseparates the rim from the 362,744 5/1887 Hebbard 273/105.4 step.

I J/ 3 l FLYING TARGET FOR TRAP SHOOTING This invention relates toimprovements in flying targets, sometimes known as clay pigeons or claytargets, suitable for use in trap shooting or the like.

Such targets are in the form of a hollow dome-shaped structure moldedfrom a suitable mixture of pitch and clay, or pitch and limestone dust,which provides a relatively fragile structure.'The weight and diameterare standardized at 100 grams and 4% inches, respectively. 1

The targets are designed to be nested for packing purposes. Because ofthis requirement, the present practice is to provide for the target aninterior surface which follows generally the contour of the outersurface. This results in a structure having a thickness which is more orless uniform, except for irregularities on the outer surface, such asthe comers of the rim and the step and possibly beads on the dome.

I have found that a higher-score target and one having improved trappingstrength can be provided if instead of having a generally smooth curvedinterior surface, that the interior surface is provided with two or moresharp interior angles.

If a fragment knocked out of or off of a target by a pellet is so smallthat it is not clearly visible, the shot will not be scored as a hit;Therefore if the target is provided with lines of potential fracturewhich tend to increase the size of the fragment, it is possible to get ahigher score.

The throwing force is exerted by the trap on the target at a portionadjacent the rim, herein referred to as a step. The step must havesufficient trapping strengt to withstand this force. Sometimes the stepis not strong enough and the target breaks in the trap.

According to my invention the sharp interior angles providecircumferentially extending lines of potential fracture which areparticularly effective because they are located on the interior surfaceof the target. Furthermore, the use of two interior angles makes itpossible to provide a heavier or thicker section for the step withoutinterfering with the desired nesting relationship. The thicker sectionfor the step improves the trapping strength. Thus this change in thecontour of the interior surface improves the target in the two respectsabove noted.

Other objects, features and advantages will become apparent as thedescription proceeds.

in the drawings:

FIG. 1 is a plan view of a target embodying my invention;

FIG. 2 is a sectional elevation taken along line 2-2 of FIG.

FIG. 3 is a section similar to FIG. 2 but showing the nesting of twostacked targets; and

FIG. 4 is an outline showing the relative proportions of the neckportion provided by the lower interior angle.

The target is an integral molded member, the various portions of whichcan be referred to as the rim 11, the step 12, the dome 13, and the chip14. The angle between the outer surface of the step and the uppersurface of the rim can be referred to as the step angle 15.

The hollow interior of the target is composed of several cylindrical orconical surfaces. The inner rim surface 17 is substantially cylindrical,being made with a taper, or draw of substantially 5. Above that is a 60conical surface 18, the cone measurements being made with respect to thecone axis. Above that is a 35 conical surface 19, and above that is a 75conical surface The intersection-of surfaces 17 and 18 provides a firstinterior angle 21 of substantially 125. The intersection of the conicalsurfaces 19 and 20 provides a second interior angle 22 of substantially140.

The intersection of conical surface 20 with the bottom surface of thechip 14 provides a third interior angle 23 of substantially 165. Allangles 21, 22 and 23 are free of fillets. Each of these interior anglesprovides a line of potential fracture, although angles 21 and 22 aremore effective than angle 23.

The surfaces 18 and 19 cooperate to provide a generally convex orprotuberant inner surface 24 for the step 12, represented by a 205interior angle 25. The importance of this configuration is that itprovides a heavier cross section for the step 12 so that it is betterable to withstand the trapping force imposed on it as explained above.The sharpness of the angle 25 is not important; this could be a roundedcorner.

The diameter of the inner rim surface 17 is greater than the externaldiameter of the step 12 so as to permit nesting of the targets, as shownin FIG. 3. Thus the first interior angle 21 is offset radially outwardof the step angle 15. This provides a neck portion 26, shown in greaterdetail in FIG. 4.

The lower surface of the rim is provided with a bead 27 which rests onthe upper surface of the rim in stacking, as shown in FIG. 3, onepurpose of which is to prevent chipping or cracking of the corners ofthe rim during handling incident to packing and unpacking.

The dome may either be a plain curved surface with or without beads, ormay be provided with step-type depressions 28as shown in Bingham US.Pat. No. 3,269,767 dated Feb. 16, 1965, as shown herein. These step-typedepressions 28 provide radial facets 29 which increase the probabilityof a hit when the point of impact is offset from the diametral line, asexplained in said patent, as well as circumferential facets 30.

Although the exact relationship between the sharp interior angles andthe larger fragments is not fully understood, it is believed that thesharp interior angle localizes a certain bending stress which ariseswhen the rim or the step is cracked. The centrifugal force due to thespin of the target develops a certain amount of hoop stress in the rim,and also in the step. If the rim is cracked by the impact of the pellet,the crack releases the hoop stress with the result that immediatelyadjacent to the crack, the interior angle 21 acts as a hinge point foroutward movement of the rim with the result that the interior angleangle is stressed. A similar stress is developed at the interior angle22 if the crack extends through both the rim and the step.

The smaller the angle, the greater the stress. I have found thatinterior angles in the range of from to exhibit a measurable degree offrangibility in comparison with angles of, say, to The presence of theprotuberant portion 24 enables one to reduce the size of the interiorangles 21 and 22 because there is a complemental relationship betweenangle 25 and angles 21 and 22; the angle 25 is preferably greater than200".

As a result of the centrifugal stress developed at the interior angles21 or 22 by the release of the hoop stress, a circumferential fracturewill occur; hence, the fragment which is torn from the target will tendto have a much greater width dimension than would be the case if theseinterior angles were not provided.

The same occurs when a pellet penetrates the rim or the step and splitsoff some of the interior surface which is likely to be sufficientlysmall as to be not visible as contrasted with an impact which is strongenough to knock off a visible segment of the rim. This puncturing of therim or the step will at least partially release the hoop stress andhence develop the centrifugal stress at the interior angles 21 or 22.

The interior angles 21, 22, 23, are made as sharp as possible tolocalize the stresses involved. The characteristic of sharpness, thatis, approach to zero radius at the apex, is obtained by accuracy informing the punch portion of the mold or die. The punch is rough cut,and then finish cut on an engine lathe to about 0.005 inches oversize.Then it is heat treated or case hardened, and thereafter surface groundto the desired dimensions by the techniques which are followed insurface grinding to a tolerance of plus or minus 0.002 to 0.003 inches.This is believed to provide for the interior angles a sharpness, orradius at the apex, of the same order of magnitude, that is,substantially less than 0.010 and quite possibly, an apex radius of from0.002 to 0.003 inches. The molding mix follows faithfully the contour ofthe punch with the result that the interior angles 21, 22, and 23 havethe same degree of sharpness as the punch.

Due to the radial offset of angles and 21, it is possible to provide avery pronounced neck portion 26 which is much tinner than the rim, asshown in FIG. 4. This neck portion 26 also contributes to thefrangibility of the target because it partially isolates the spinningmass of the rim from the spinning mass of the step. A sudden change inthe rotational inertia of either, caused by the impact of a pellet, willstress the neck portion in a circumferential direction, adding to thecentrifugal stress when the hoop stress is released.

It will be noted that the neck portion 26, being located beneath thestep angle 15, does not weaken the step section.

The outer vertical surfaces of the rim portion 11 and the step portion12 are cylindrical, and the upper corner of the rim portion preferablyis rounded as shown in FIG. 4. Due to shrinkage in the mold, no draw isnecessary on the outer surfaces, but because of this shrinkage, a drawis required for the surface 17 which, as pointed out above, issubstantially 5.

In the embodiment shown, the rim 11 is substantially threesixteenthsinch thick and seven-sixteenths inch high including the head 27. Theminimum neck thickness is substantially three thirty-seconds inchmeasured along the dotted line 31 (FIG. 4) and the neck length measuredparallel to the surface 18 is substantially one-eighth inch. The overallheight of the target is substantially 1 inch, the diameter being 4%inches. The depth of the depressions 28, measured along the facet 30 isfrom three thirty-seconds to one-eighth inch, and the depression widthvaries from one-sixteenth to one-eighth inch. The step 12 is 3% inchesin diameter and one-fourth inch high.

lclaim:

1. A flying target of the hollow dome-shaped type having a rim portion,a step portion, a curved dome portion, and a chip portion, the outersurface of said step portion and the upper surface of said rim portionforming a step angle, the internal diameter of the rim portion beinggreater than the external diameter of the step portion to permit nestingof stacked targets, the internal surface of said target including aplurality of substantially conical surfaces which intersect each otherto provide two obtuse interior angles in the range of from 120 to 150and an inwardly protuberant portion therebetween, the lower interiorangle being located beneath and radially outward of said step angle, andthe upper interior angle being located beneath said dome portion and atsubstantially the level of the upper surface of said step portion, saidinwardly protuberant portion extending from said lower interior angle tosaid upper interior angle to provide an increased thickness for saidstep portion but being clear of the dome of a lower ad- 5 jacent targetwhen nested therewith, each of said interior angles providing a line ofpotential fracture which extends in a circumferential direction, andbeing subject to a centrifugal stress when intersected by a verticallyextending fracture.

2. A flying target as claimed in claim 1 in which said lower interiorangle is substantially and said upper interior angle is substantially 3.A flying target as claimed in claim 1 having a third interior anglebetween a conical surface and the lower surface of said chip portion.

4. A flying target as claimed in claim 3 in which said third interiorangle is substantially 5. A flying target as claimed in claim I in whichthe sharpness of said interior angles, as measured by the radius at theapex is less than .010 inches.

6. A flying target as claimed in claim I in which said dome portion isprovided with a plurality of steplike depressions providing radiallydisposed facets.

7. A flying target as claimed in claim 1 in which the conical surfacesbounding said protuberant portion intersect to provide an interior anglegreater than 200.

8. A flying target as claimed in claim 1 in which one of said conicalsurfaces underlies said step angle and cooperates therewith to provide aneck portion connecting said step and rim portions, said neck portion atits narrowest point having a thickness dimension substantially less thanthe thickness of said rim portion.

9. A flying target as claimed in claim 8 in which said neck thicknessdimension is substantially 3/ 32 inches.

10. A flying target as claimed 111 clarm 8 in which sard lower interiorangle is substantially 125.

11. A flying target of the hollow dome-shaped type having a rim portion,a step portion, a dome portion, and a chip portion, the internal surfaceof said target including four substantially conical surfaces whichintersect each other and having substantially the following angularmeasurements with respect to the cone axis, starting from the rimportion and reading in order: 5, 60, 35, and 75.

1. A flying target of the hollow dome-shaped type having a rim portion,a step portion, a curved dome portion, and a chip portion, the outersurface of said step portion and the upper surface of said rim portionforming a step angle, the internal diameter of the rim portion beinggreater than the external diameter of the step portion to permit nestingof stacked targets, the internal surface of said target including aplurality of substantially conical surfaces which intersect each otherto provide two obtuse interior angles in the range of from 120* to 150*and an inwardly protuberant portion therebetween, the lower interiorangle being lOcated beneath and radially outward of said step angle, andthe upper interior angle being located beneath said dome portion and atsubstantially the level of the upper surface of said step portion, saidinwardly protuberant portion extending from said lower interior angle tosaid upper interior angle to provide an increased thickness for saidstep portion but being clear of the dome of a lower adjacent target whennested therewith, each of said interior angles providing a line ofpotential fracture which extends in a circumferential direction, andbeing subject to a centrifugal stress when intersected by a verticallyextending fracture.
 2. A flying target as claimed in claim 1 in whichsaid lower interior angle is substantially 125* and said upper interiorangle is substantially 140*.
 3. A flying target as claimed in claim 1having a third interior angle between a conical surface and the lowersurface of said chip portion.
 4. A flying target as claimed in claim 3in which said third interior angle is substantially 165*.
 5. A flyingtarget as claimed in claim 1 in which the sharpness of said interiorangles, as measured by the radius at the apex is less than .010 inches.6. A flying target as claimed in claim 1 in which said dome portion isprovided with a plurality of steplike depressions providing radiallydisposed facets.
 7. A flying target as claimed in claim 1 in which theconical surfaces bounding said protuberant portion intersect to providean interior angle greater than 200*.
 8. A flying target as claimed inclaim 1 in which one of said conical surfaces underlies said step angleand cooperates therewith to provide a neck portion connecting said stepand rim portions, said neck portion at its narrowest point having athickness dimension substantially less than the thickness of said rimportion.
 9. A flying target as claimed in claim 8 in which said neckthickness dimension is substantially 3/32 inches.
 10. A flying target asclaimed in claim 8 in which said lower interior angle is substantially125*.
 11. A flying target of the hollow dome-shaped type having a rimportion, a step portion, a dome portion, and a chip portion, theinternal surface of said target including four substantially conicalsurfaces which intersect each other and having substantially thefollowing angular measurements with respect to the cone axis, startingfrom the rim portion and reading in order: 5*, 60*, 35*, and 75*.